1. Technical Field
This invention relates generally to step drill bits and more particularly to a step drill bits having a removable drill bit tip and more particularly to a step drill bit having three cutting edges.
2. State of the Art
There are various types of drill bits that are used in construction, fabrication or other types of manufacturing processes. Drill bits come in various sizes and for various purposes. Among the many different types of drill bits are step drill bits.
A step bit is a conical shaped bit with a stair-step profile. Due to the design of a step bit, a single bit can be used for drilling a wide range of hole sizes. The bits my come in various sizes having varying step sizes to allow a user to utilize the bit that has the proper step sizes to cut holes with the desired diameter.
Step bits are most commonly used in general construction, electrical applications within buildings and plumbing. One step drill bit may be used to drill a range of holes necessary for the particular type of construction or work being performed by the user. The bits are more commonly used on softer materials, such as plywood, particle board, drywall, acrylic, laminate, and the like. However, particular step bits may be used on other harder materials such as sheet metal and the like.
There are however, drawbacks to the conventional step drill bits. Conventional step drill bits come with one or two cutting edges and each has its own limitations. A step bit with one cutting edge is commonly used to because it allows the user to cut holes with little wobble or little inaccuracy. However, having only one cutting edge has greater wear because only one edge doing all of the cutting and as that edge performs the cuts, it wears quickly. Additionally, one cutting edge is inefficient because each cut is performed every revolution of the drill bit.
Conventional step bits having two cutting edges increases the efficiency of the drilling of the bit by having two edges allowing for the cutting to be performed every half turn of the step bit. However, step bits with two cutting has less accuracy in obtaining the proper hole diameter because there tends to be wobble in the bit and less stability during the drilling process. Further, the efficiency of the cut is limited to cutting a particular diameter every half turn and the wear of the edges is longer that the step bit with one cutting edge, but it is still limited in life.
Accordingly, there is a need in the field of step drill bits for an improved step drill bit.